Sprint to Church Point - this segment is the traditional sprint segment for our group - typically the stronger riders would break away from the bunch just after a short sharp crest and then it's full steam ahead and may the best rider wins. Today three of us broke free so I was guaranteed at least 3rd position - and I was 3rd, following the wake of two very strong riders:

Here's my Velcro mount on my roadie. Industrial sticky velcro on the frame and the Camera housing. I then have a strap around it to keep it tight and stop it wobbling around, this is actually from my AyUp kit and is also a type of velcro. I also have a tether made from Garmin mount O-rings. I don't like having the camera mounted on my helmet so I'm very happy with this solution.

DaveOZ wrote:Here's my Velcro mount on my roadie. Industrial sticky velcro on the frame and the Camera housing. I then have a strap around it to keep it tight and stop it wobbling around, this is actually from my AyUp kit and is also a type of velcro. I also have a tether made from Garmin mount O-rings. I don't like having the camera mounted on my helmet so I'm very happy with this solution.

Congratulations - you seem to have found a flat spot for the velcro to work, and the strap prevents the wobbling that you normally get with velcro. Thanks for sharing.

Waterfall to Sutherland sprint. It was relatively slow start - but my Garmin showed a max speed just over 70 km/h during the Mad Mile - around 17-18 minutes into the video (interestingly, Strava reports my power as 474 watts during the Mad Mile).

Christine Tham wrote:Waterfall to Sutherland sprint. It was relatively slow start - but my Garmin showed a max speed just over 70 km/h during the Mad Mile - around 17-18 minutes into the video (interestingly, Strava reports my power as 474 watts during the Mad Mile).

Nice ride Christine. Strava power figures are rubbish though. Strava reports my peak 5 min power at 594W. If only you could see my pathetic legs. Whatever the output, you were flyin ...

Rhubarb wrote:Nice ride Christine. Strava power figures are rubbish though. Strava reports my peak 5 min power at 594W. If only you could see my pathetic legs. Whatever the output, you were flyin ...

Strava overstates power output when I'm sucking wheel, which I was for the whole ride. Also I think there was a slight tailwind. Normally I would be struggling to exceed 300 watts on the stationary, so I'm guessing my power output is probably 350 during the Mad Mile?

It wasn't my best ride (I've never won the sprint, but have come 2nd or 3rd I think with a bit of time in front) but it shows I am slowly getting back into form after a very lazy year.

Rhubarb wrote:Nice ride Christine. Strava power figures are rubbish though. Strava reports my peak 5 min power at 594W. If only you could see my pathetic legs. Whatever the output, you were flyin ...

Strava overstates power output when I'm sucking wheel, which I was for the whole ride. Also I think there was a slight tailwind. Normally I would be struggling to exceed 300 watts on the stationary, so I'm guessing my power output is probably 350 during the Mad Mile?

It wasn't my best ride (I've never won the sprint, but have come 2nd or 3rd I think with a bit of time in front) but it shows I am slowly getting back into form after a very lazy year.

From my experience with a power meter, it over estimates ALL THE TIME! Sometimes by a little, sometimes by heaps. It also can't account for wind conditions.

A fast and furious segment from Galston to Berowra Waters with the Renegade A group. I was nearly dropped at one stage - fortunately the guys eased up for me (and the rest of the bunch behind me) to catch up.

norbs wrote:I am curious how you know how much power you put out with out a power meter.

I am curious how you would know I have never used one.

I am also curious why you find my post hilarious. I would have thought it's obvious - the Strava power estimator is based on a number of assumptions about the rider physique, profile and riding conditions. If you say it's over-estimating for you (and assuming your power meter is accurate - I've tested a few power meters and they vary a bit so I don't think they are very accurate to start with) then clearly the assumptions don't fit you. Doesn't mean they won't fit someone else.

For me, the Strava power figures for my daily commute are roughly on par with the power figures from a power meter.

Based on assumptions. And their road inclinations as well, which are iffy at best.

Rider physique. Based on what? Men and women? How heavy you are? Whether you ride in the drops or tops?

The type of bike you ride? Whether there is wind?

Whether you have used one or not doesn't really come into it. Unless you know what power you are putting out, or have compared rides with a power meter that you don't upload to Strava, I am at a loss to know how accurate Strava is.

Doesn't matter, I am out of the argument, this thread is about a camera. Sorry to all for taking it off topic.

Strava's "accuracy" will depend on all those factors you have mentioned, and then some. Actually, at 45 km/h, around 70-80% of the power is used in overcoming air resistance, so I would expect the rider's aero profile will become a dominant factor as the speed increases.

However, it's not about how accurate Strava is in absolute terms, but how consistent.

As I mentioned before, I was surprised at how power meters vary in their readings. I was told this was normal - the important thing is not the absolute numbers but relative numbers over time.

The main issue about Strava is not whether it's over or under estimating (and the power meter you are comparing it with may not be that accurate in absolute terms anyway). The issue is consistency - there is no way Strava power numbers will be as consistent or as reliable as a power meter in terms of relative accuracy. I wouldn't trust them as a training aid, but then I am a casual rider - I ride for fun, I don't "train."

For what it's worth, I jumped onto the stationary bike this morning as it was drizzling outside, and reconfirmed that my peak power output (corresponding to max heart rate) is around 300-350 watts, and there is a very high correlation between average power output and heart rate.

Comparing the Strava power numbers against heart rate for my Waterfall ride, it would seem Strava is primarily using the heart rate as a gauge of power. But because the heart rate is a lagging indicator, it adjusts it based on other conditions like speed and incline. Strava also uses the heart rate to determine whether the rider is pedalling or coasting.

Based on that, I would suggest Strava's "accuracy" probably depends on it's assumptions about the rider fitness within age group and gender parameters. Also, the faster your heart responds to changing conditions the more accurate it will be.

DaveOZ wrote:For the record I managed to record a full 100km ride yesterday on my Sony ActionCam on 720p setting (32Gb card) using two batteries. I even washed one of the batteries in my jersey and it survived!!

From said ride.

The only issue with that mount point Dave is the fact it picks up all the drive train noise through the frame. Video quality is great.

Had mine out for a couple of test rides. First battery charge was good enough for going through to check the camera settings and then record at 1080p with steadyshot on for a continuous 2 hours 19 minutes and 48 seconds, just 9 seconds short of me pushing the stop button on the Garmin.

The waterproof housing really needs the anti fog satchel thing as I had to wipe condensation off a few times and as noted with Dave's video there was a lot of drivetrain and road (or in my case off road) noise that really makes the audio unusable. I also think that mounting the camera directly forward of the bars probably made vibration worse than if I had mounted upside down underneath the bars but will play with this and some other mounting options as I go.

Still overall very happy with the performance.

I'll post some videos when I get around to installing some software to cut out bits worth posting.

DaveOZ wrote:For the record I managed to record a full 100km ride yesterday on my Sony ActionCam on 720p setting (32Gb card) using two batteries. I even washed one of the batteries in my jersey and it survived!!

From said ride.

The only issue with that mount point Dave is the fact it picks up all the drive train noise through the frame. Video quality is great.

sblack wrote:Had mine out for a couple of test rides. First battery charge was good enough for going through to check the camera settings and then record at 1080p with steadyshot on for a continuous 2 hours 19 minutes and 48 seconds, just 9 seconds short of me pushing the stop button on the Garmin.

Thanks for doing the measurement.

For some reason or another - the first time I used it I recorded over 3 hours (not continuously - over a span of several commutes) before the battery died. But lately on a long ride, it seems the battery will die just under 2.5 hours (if I don't carry a spare battery, I miss out on the last 30 minutes of a 3 hour ride).

I'm feeling really lazy and fat at the moment - just back from the Hunter Valley and I haven't cycled for a week. Dreading the thought of riding tomorrow - will probably cramp due to lack of fitness. Strava sent me a nice welcome home email this morning to say someone has stolen my QOM

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